Southwest of St. Louis, the Chubb Trail is a locally favored 7 mile mountain biking route with rocky terrain and nasty dropoffs. Its marked as 7 miles long beginning with a very challenging 3 miles through the wooded hillside with some challenging roots, rocks, and gravelly climbs with all of the above. You are progressing (generally) down to the Merramec (sp?) River for about 2 miles of easy winding riverside trail before a mile of gravel road ending in a long and moderately steep climb to Lone Elk Park (where you either hop into a friends vehicle or suck it up for the mountain bike ride back!). NOTE: VERY treacherous when the trail is wet (rock and roots become very slick).
To reach the mountain biking trailhead from St. Louis, follow US44 west to exit #265 (Lewis Road). Pass into Tyson Park and proceed to the end of the road.